There were some off-by-one bugs that could overwrite the first pixel in the next scanline. Also the ClipRect handling didn't match the CopyBlend function's interpretation. CopyBlend excludes Right/Bottom whereas TMaskRenderer included them. And because TMaskRenderer is a replacement for the Polygon()+CopyBlend(BlendMask) code that was in EraseOutsidePaths, it should give the exact same result.
The TMaskRenderer now also handles skipped scanlines for paths with disjunct polygons. For this the Rasterize() function has been extended to notify the renderer about the skipped scanlines.
ahausladen
commented
1 month ago
This PR fixes some bugs in the new TMaskRenderer.
There were some off-by-one bugs that could overwrite the first pixel in the next scanline. Also the ClipRect handling didn't match the CopyBlend function's interpretation. CopyBlend excludes Right/Bottom whereas TMaskRenderer included them. And because TMaskRenderer is a replacement for the
Polygon()+CopyBlend(BlendMask)code that was in EraseOutsidePaths, it should give the exact same result.The TMaskRenderer now also handles skipped scanlines for paths with disjunct polygons. For this the Rasterize() function has been extended to notify the renderer about the skipped scanlines.